Device for making a skin incision

ABSTRACT

A device for forming a skin incision comprising a base plate having a lower surface adapted to be placed flush against the skin and having an elongated aperture therein, a support member for an instrument having a cutting edge aligned with said aperture, means mounting said instrument for rotation about an axis substantially parallel with the bottom surface of the base plate between first and second limit positions whereby upon actuation of said instrument about said axis between said limit positions, said cutting edge moves through an arc of a circle from points above the lower surface of the base plate at the limit positions to an area below the lower surface between the limit positions to produce an incision of predetermined length and depth.

United States Patent [191 Begg et al.

[4 1 Sept. 2, 1975 DEVICE FOR MAKING A SKIN INCISION [75] Inventors: Geoffrey Stephen Begg, Heidelberg; Nils Berti] Jacobson, Solna, both of Sweden [73] Assign ee: Medinova, AB, Solna, Sweden [22] Filed: Aug. 13, 1973 [21] Appl. No.: 388,099

[30] Foreign Application Priority Data 3,760,809 9/1973 Campbell, Jr 128/2 R Primary Examiner-Channing L. Pace Attorney, Agent, or Firm--HOWson and Howson [57] ABSTRACT A device for forming a skin incision comprising a base plate having a lower surface adapted to be placed flush against the skin and having an elongated aperture therein, a support member for an instrument having a cutting edge aligned with said aperture, means mounting said instrument for rotation about an axis substantially parallel with the bottom surface of the base plate between first and second limit positions whereby upon actuation of said instrument about said axis between said limit positions, said cutting edge moves through an arc of a circle from points above the lower surface of the base plate at the limit positions to an area below the lower surface between the limit positions to produce an incision of predetermined length and depth.

9 Claims, 3 Drawing Figures f DEVICE FOR KING A SKIN TNCKSION BAC KGROUND .OF THE INVENTION The present invention relates to a device for providing a skin incision in order to cause a bleeding making it possible to determine the bleeding time, i.e. the duration of the bleeding after the incision has been made.

Most people have relatively short bleeding times, but before an operation is started it is important to examine the patient in respect of his bleeding time. If the patient has a long bleeding. time, i.e. reduced haemostatic properties, certain precautions have to be taken.

Up to now a usual surgical knife or scalpel or a simple mechanical device has been used for making the skin incision. This method has the obvious drawback that the depth of the skin incision varies dependent on the pressure applied to the knife and on the mechanical properties of the patients skin. The method requires a great skill for giving reproducable values. A further drawback is that the method is unsuitable for psychological reasons, especially in connection with the determination of the bleeding times of children, as the children are frightened when the incision is made by means of a knife.

SUMMARY OF THE INVENTION The object of the present invention is to provide a device for making skin incisions which does not have the drawbacks mentioned above.

In accordance with the invention the device for making a skin incision comprises a base plate adapted to be placed against the skin with a bottom surface and a cutting blade rotatably mounted with respect to an axis substantially parallel with the base plate, the distances between the axis and the bottom surface of the base plate and between the axis and the cutting edge or point of the cutting blade being so related that the cutting edge or point describes an arc of a circle below the bottom surface of the base plate when the cutting blade is rotated around said axis for providing a skin incision of predetermined length and depth.

By means of the device according to the invention it is possible to make a skin incision having a depth dependent on the distance relationship mentioned above and a length dependent on said relationship and the distance between the axis and the cutting edge or point of the cutting blade.

A further advantage is the fact that the device can be designed so that it does not frighten the patient.

BRIEF DESCRIPTION OF THE FIGURES The invention is explained with reference to the attached drawings showing two different embodiments of the device according to the invention:

FIG. 1 is a perspective view of a first embodiment of the device according to the invention.

FIGS. 2 and 3 are perspective views in different directions of a second embodiment of a device according to the invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS The device shown in FIG. 1 consists of a base plate 1 having an elongated aperture 2 and a support member 3 connected with the base plate. At the upper end of the support member there is mounted a shaft (not shown) which is rotatable by means of an eccentric disc 4. In said shaft there is eccentrically mounted another shaft 5 rotatably supporting an arm 6. The arm 6 is provided with stop means 7 and 8 restricting the rotation of the arm 6. The stop means form finger grips 7 and 8 intended for the thumb and. the middle finger, respectively. The lower part of the arm 6 is provided with pins 9 and 10 to which a knife 11 is fastened. The pin 10 is resiliently supported in relation to the pin 9. The resiliency is provided by means of a slot 12 formed in the arm 6.

. The knife 11 can be fastened to the pins 9 and 10 without being unsterilized. The knife is fastened by being pressed against the pins which are conical at their outer ends. After being used, the knife is removed by pressing the knife from the pins 9 and 10 with the finger.

After a sterilized knife 11 has been fastened to the arm 6, the device is used in the following way. The edge of the knife is adjusted in relation to the bottom surface of the base plate. This adjustment is provided by turning the eccentric disc so that the knife edge is only just sightable below the elongated aperture 2 when the arm 6 is in a position wherein the stop means 7 engages the support member 3. j

The device is placed on the patients skin with the bottom surface of the base plate 1 in contact therewith, usually on the upper side of the fore arm. The device is grasped as shown in the Figure with the stop means 7 engaging the support member 3. By pressing the arm 6 with the middle finger the arm is rotated counterclockwise to a position wherein the other stop means 8 engages the base plate. Thereby, the knife is rotated, the edge or point of the knife describing an arc below the bottom surface of the base plate making an incision of predetermined depth and length in the skin.

FIGS. 2 and 3 show a second embodiment of the device according to the invention comprising a base plate 13 having a support member 14 connected therewith. An arc-shaped member 15 is partly received in and guided by a groove 16 having the same arc-shape as the member 15. The member 15 is retained in the groove 16 by means of a pin 17 which engages the member 15 and extends through a slot 18 formed in the support member 14 and is at its outer end provided with an enlargement 19. Thus, the arc-shaped member 15 is movable along an arc of a circle between two end positions wherein the pin 17 engages the opposite ends of the slot 18.

The arc-shaped member supports the knife 20 fixed to the member 15 by means of pins 21 extending through a slot 22 formed in the knife 20 into the member 15 and formed at their outer ends with enlargements pressing the knife against the member 15.

Preferably the device according to FIGS. 2 and 3 is of the disposable kind for which reason the knife is fixedly connected with the arc-shaped member 15 in an adjusted position in relation to the base plate 13.

In one of the end positions, which also constitutes the starting position when the device is to be used, a projection 23 engages a cavity (not shown) formed in a portion 24 of the support member 14 made resilient by means of two slots 25. The projection 23 and the corresponding cavity constitute a snap detent resiliently retaining the arc-shaped member 15 and the knife supported thereby in the starting position.

The upper end of the support member 14 and the ends of the arc-shaped member 15 are shaped to constitute finger grips to be engaged when the device is to be used.

The base plate 13 is placed with the bottom surface on the patients skin, the forefinger engaging the finger grip at the upper end of the support member for retaining the device against the skin and the middle finger and the thumb engaging the finger grips at the ends of the arc-shaped member 15 for manipulating the member 15. When the member 15 is displaced along the groove 16 the edge or point of the knife 20 describes an arc of a circle below the bottom surface of the base plate making an incision in the skin according to the same principles as described with reference to the embodiment of FIG. 1.

The invention can be modified within the scope of the following claims.

What is claimed is:

1. A device for forming a skin incision comprising a base plate having a lower face adapted to be placed flush against the skin, means defining an elongated aperture in the base plate, a support member projecting from the upper face of said base plate adjacent said aperture, means mounting an instrument having a cutting edge on said support member for limited angular movement about a fixed axis so that upon pivotal movement of said instrument about said axis the cutting edge moves from a point above the plane of the lower face of the base plate adjacent one end of said aperture in an arcuate path through said aperture below the plane of the lower face of the base plate to a point above the plane of the lower face of the base plate adjacent the opposite end of said aperture to produce an incision of predetermined length and depth.

2. A device as claimed in claim 1 in which the cutting instrument is mounted on an arm pivotally mounted to said support member and rotatable in relation to the base plate.

3. A device as claimed in claim 2, comprising stop means restricting the rotation of the arm.

4. A device as claimed in claim 3, in which said stop means are supported by the arm and are formed as finger grips facilitating the manipulation of the arm.

5. A device as claimed in claim 2, in which the arm is mounted by means of an eccentric device adjustably supporting the arm for varying the distance between the axis and the bottom surface of the base plate.

6. A device as claimed in claim 1 including means defining an arcuate shaped groove in said support member and wherein said means mounting said instrument is of an arcuate shape engageable in said groove and displaceable therein to effect displacement of the cutting edge of said instrument along said are of a circle.

7. A device as claimed in claim 6, in which the support member and the arc-shaped member are provided with finger grips for facilitating the manipulation of the device.

8. A device as claimed in claim 6, in which the areshaped member is provided with a pin extending through a slot formed in the support member, the ends of the slot defining the end positions of the displacement of the arc-shaped member and the knife.

9. A device as claimed in claim 6, comprising a snap detent for releasably maintaining the cutting instrument in one of the end positions defining the start position for the rotation of the cutting blade. 

1. A device for forming a skin incision comprising a base plate having a lower face adapted to be placed flush against the skin, means defining an elongated aperture in the base plate, a support member projecting from the upper face of said base plate adjacent said aperture, means mounting an instrument having a cutting edge on said support member for limited angular movement about a fixed axis so that upon pivotal movement of said instrument about said axis the cutting edge moves from a point above the plane of the lower face of the base plate adjacent one end of said aperture in an arcuate path through said aperture below the plane of the lower face of the base plate to a point above the plane of the lower face of the base plate adjacent the opposite end of said aperture to produce an incision of predetermined length and depth.
 2. A device as claimed in claim 1 in which the cutting instrument is mounted on an arm pivotally mounted to said support member and rotatable in relation to the base plate.
 3. A device as claimed in claim 2, comprising stop means restricting the rotation of the arm.
 4. A device as claimed in claim 3, in which said stop means are supported by the arm and are formed as finger grips facilitating the manipulation of the arm.
 5. A device as claimed in claim 2, in which the arm is mounted by means of an eccentric device adjustably supporting the arm for varying the distance between the axis and the bottom surface of the base plate.
 6. A device as claimed in claim 1 including means defining an arcuate shaped groove in said support member and wherein said means mounting said instrument is of an arcuate shape engageable in said groove and displaceable therein to effect displacement of the cutting edge of said instrument along said arc of a circle.
 7. A device as claimed in claim 6, in which the support member and the arc-shaped member are provided with finger grips for facilitating the manipulation of the device.
 8. A device as claimed in claim 6, in which the arc-shaped member is provided with a pin extending through a slot formed in the support member, the ends of the slot defining the end positions of the displacement of the arc-shaped member and the knife.
 9. A device as claimed in claim 6, comprising a snap detent for releasably maintaining the cutting instrument in one of the end positions defining the start position for the rotation of the cutting blade. 